html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}

body {
    background-image: url('../image/bg.jpg');
    background-size: 100% 100%;
    background-repeat: no-repeat;
}

.login_form {
    width: 400px;
    height: 400px;
    text-align: center;
    margin: 0 auto;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

.head {
    padding: 18px 0;
}

.head h2 {
    margin: 0;
}

.content input {
    margin: 10px;
    padding: 10px;
    width: 80%;
    outline: none;
    border: none;
    border-radius: 5px;
    background: rgba(255, 255, 255, 0.5);
    font-size: 18px;
}

.content button {
    width: 85%;
    margin-top: 20px;
    padding: 10px;
    border: none;
    border-radius: 5px;
    font-size: 20px;
    font-weight: bold;
}